Question

7x-4y=-7
5x+y=22
how do I solve this using substitution?

Answer 1

A) 7x-4y=-7
B) 5x+y=22
We can rearrange equation B)
B) y = 22 -5x Then we can substitute it into equation A
A) 7x -4*(22 -5x) = -7
A) 7x -88 +20x = -7
A) 7x +20x = 81
A) 27x = 81
x = 3
5*3 + y = 22
y = 7